"I'm wondering why my Galaxy S5 won't auto-connect to a wireless network even if it is in range...I have to do it manually."
While there have been several owners of Samsung Galaxy S3, complaining about their device that is unable to auto-connect to a wireless network in range, only a few Galaxy S5 owners have reported about the same issue so far, saying they have to “manually connect to an available wireless network.”
For the sake of those encountering similar Wi-Fi problem on their GS5 device, we came up with the following suggestions.
Typically, a device is unable to auto-connect to an available wireless network because the Wi-Fi network in range is hidden or not broadcasting the SSID.
We therefore suggest verifying of the Wi-Fi network you are trying to connect to first and make sure it is not hidden or not broadcasting the SSID. Because when the network is hidden, it will not be recognized by the device even if it is within range.
Another suggestion is to try "forgetting" the network on your device and reconfigure it.
Also verify if your Wi-Fi router is configured correctly. Incorrect configuration of the wireless router may also cause the same problem to occur on the phone. You may need to contact your Internet Service Provider in this case.